Welding electrodes are made from steel with a copper coating. For this reason they need to be stored in a moisture free environment. If you let them corrode or get mucky then you will have a terrible time welding with them.
Mine have been sitting in a black plastic sack since I bought them so I’ve been looking for a better solution. Float tubes from a fishing shop were suggest but my local fishing shop did not have any long enough and gave me a very evil look when I mentioned it was for welding rods.
Last week in the shed I spotted a piece of grey plastic tube that was just the right length and a further search in the store pile and I found another. I also had some branches left from making the bush saw last year so I turned up some end stoppers with my mini lathe and gave them a coat of Danish Oil. Once that’s dry, I’ll put some labels on the ends and my electrodes with have a new home.